Multi-platen press



Aug. 28, 1962 E. SIEMPELKAMP MULTI-MATEN PRESS 4 Sheets-Sheet 1 FiledFeb. 2, 1960 Aug. 28, 1962 E. SIEMPELKAMP 3,050,777

MULTI-PLATEN PRESS Filed Feb. 2, 1960 4 Sheets-Sheet 2 .7n ven/or:

Eugen, SiemPe kamp Aug. 28, 1962 E. SIEMPELKAMP MULTI-PLATEN PRESS 4Sheets-Sheet 3 Filed Feb. 2, 1960 Jnvemor: Eugen Siem/oe/fam/o BY wf@Agen-l:

Aug 28, 1962 Filed Feb 2. 1960 E. SIEMPELKAMP MULTI-PLATEN PRESS 4Sheets-Sheet 4 ilite 3,959,777' MULTl-PLATEN PRESS Eugen Siempelkamp,Hohenzoliernstr. 69, Krefeld, Germany Filed Feb. 2, 196i), Ser. No.6,183 Claims priority, application Germany Feb. 5, 1959 9 Claims. tCl.it-le) My present invention relates to a multi-platen press and, moreparticularly, to platen-spacing means for such presses.

Multi-platen presses, and primarily those employed for the heatedcompression and curing of cellulose-liber sheets (eg. iiberboard), havebeen provided heretofore with lazy-tongs or similar mechanisms adaptedto maintain the spacing between the several platens during the closingof the press. These lever linkages do not, however, compensateetlectively for the omission of sheets as a result or" a faultypress-charging operation or for the varying thicknesses of the sheets.Thus, the major compacting force of a hydraulic press bed is oftenapplied only to a few of the charged sheets, or unequally to the entirecharge.

lt is, therefore, the general object of my invention to provide amulti-platen press ,adapted to obviate the abovementioned disadvantages.

A more specific object of the invention is to provide improvedplaten-spacing means for multi-platen presses.

According to a feature of my invention, the sheet-'supporting platens ofa multi-platen press are elevated concurrently with the elevation of thebed plate, but at different rates corresponding to the distance eachplaten must be vertically displaced to reach the point at whichcompression of the charge between the -bed plate and the head plate ofthe press commences. Generally speaking, the lowest platen (nearest thebed plate) will require the greatest displacement while the uppermostplaten (nearest the head plate) will require the least. Upon reachingthe point at which pressure is applied by the bed plate, or at least thepoint in the closing of the press at which such pressure would normallycommence in the presence of .a full charge, the platen-spacing apparatusis rendered inoperative, in accordance with the invention, so that nomechanical strains will develop from any unequal spacings as caused, forexample, by the absence of one or more rough sheets between the platensor from differences in the thicknesses of the inserted sheets.Advantageously, the platen-spacing apparatus may subsequently be causedto function again for the gradual lowering of the platens aftercompaction or at some other point in the press cycle to assist inreadying the press for the next charge.

According to another feature of the invention, the platens are raisedand lowered by individual mechanical links preferably in the form ofcables secured to a suitable transmission mernber, such .as a steppulley. The cables attached to the lowest platens may then engage thelargest-diameter steps of the pulleys while the successively higherplatens are connected with respective smaller-diameter steps. Thus, uponrotation of the pulleys either independently of or in response to theelevation of the bed plate, the step pulleys taire up the cables inproportion to the required vertical displacement of each platen, therebyclosing the press gradually and smoothly and without requiring the bedplate or the lower platens to support upper, unloaded platens.Advantageously, the rotation of the pulleys may be coupled to themovement of a hydraulically elevatable structure, eg. the bed plateitself, via tractive members and suitable direction-changing meanswhereby the closure stroke of the bed plate prior to compression isutilized to operate the spacing apparatus. The latter may then be ren-'l'i Patented Aug. 28, 1962 dered inoperative, for the purpose mentionedabove, by slackening the tractive members.

According to a more speciiic feature of the invention, the spacingapparatus is uncoupled from the drive means therefor by halting the riseof the elevatable structure accompanying the closing movement of the bedplate while permitting the latter to continue its stroke, therebycompressing the sheets while concurrently slackening the cables. Thespacing apparatus may also be engaged or disengaged by means ofelectrical and hydraulic control circuits actuated directly by themotion of the bed plate.

The above and other objects, features and advantages of my presentinvention will become more readily apparent from the followingdescription, reference being made to the accompanying drawing in which:

FIG. l is a somewhat schematic front-elevational view, with parts brokenaway and in section, of a multi-platen press according to the invention;

PEG. 2 is a view, similar to FIG. l, of a second embodiment of theinvention;

FlG. 3 is a side-elevational view, with parts broken awa of theembodiment of FlG. 2; and

FIG. 4 is a schematic circuit diagram of this embodiment.

ln FlG. l I show a multi-platen press in the open condition thereof,comprising a generally rectangular frame l. A bed plate 3, verticallydisplaceable by a hydraulic piston 2b received in cylinder 2a, isprovided between the front and rear members of frame l to compressroughly formed cellulose-liber sheets 2l, carried on a plurality ofvertically spaced platens 4, against a head plate 2Q. The platens 4iareeach supported by four cables epending from step pulleys 5 journaled atthe tour upper corners of the press frame. The pulleys 5 are providedwith steps of progressively increasing diameter, respectivelyproportional to the requisite displacement of each platen during theclosing of the press. The uppermost platen is therefore connected to thesmallestdiameter step while the cables 6 of the lowest platen aresecured to the largest-diameter step. Advantageously, the cables arejoined to the platens 4 at lugs Z2, dimensioned and staggered tomaintain the cables in plumb despite the dillerent radii and axialspacing of the steps. Each pulley 5 is driven by a cable 7 secured tothe driving step thereof and partly wound therearound. The cables 7 arepassed about direction-changing and tensioning pulleys 8 and connectedto bed plate 3 at lugs 23. Each pulley 8, at one of the four lowercorners of the press frame l, is supported on a vertically displaceablepiston 9 received in a cylinder 1d. Each pulley 5 is also provided witha ring of ratchet teeth 2 engageable by a pawl il. The latter may beremoved from engagement with the ratchet teeth by .a release mechanisml2, such as a solenoid, actuatable via an electric circuit arrangementcomprising a source of current Z5 and a pressure-sensitive switchschematically indicated .at 26. The master compression cylinder 2a issupplied with fluid from a reservoir 27 via a pump 28, a pressure valve29 and a distributing valve 33, while the cylinders 14 are supplied withfluid from the pump via valve 29.

In operation, upon the charging of the press with the sheets 21, thehandle of distributing valve 33 is actuated to permit a ow of fluidunder pressure from' the pump 2S through valve `29 and by way ofconduits 32Y and 3'4, to the cylinder 2a, thereby raising piston 2b andbed plate 3. Simultaneously, 4fluid ows from the pressure main 35through valve 29 and a lbore provided in the armature 29' thereof toconduit 3G. From this conduit, uid enters the cylinders 14 above thehead of pistons 9, thereby locking these pistons in the position shownin FIG. 1 to tension the cables 7. As bed plate 3 rises of pulleys v8`to permit the Y similarly provided Ving valve 40 nected in a circuitincluding an `55b lie in series withV VV.previously described, and the'is inserted in to close the press,Y the vertical movement of the plateisA V2a is transmitted to pressure valveV 29 and causes a down-Y warddisplacement of the diaphragm 29a thereof along with the plunger 29'secured thereto. The bore of this armature then becomes aligned withthat of return tube 36 whereby uid can return from cylinders 14 throughconduit'31 into the reservoir 27. Piston 9, no longer held againstvertical displacement by -uid pressure, rises under the tension of cable7 to slacken the latter so that further elevation of the bed plate 3Iwill not transmit motion to the pulleys 5 which are locked againstreverse movement by the pawls 11 engaging -appropriate teeth of theirratchet ringsY 24; When the hydraulic pressure attains apredetermined-maximum, switch 26, linked with valve 29 by a tube 26', istripped to activatesolenoids 12, therebyV disengaging the pawls 11 ,fromtoothed rings 24 and Afreeing the pulleys 5 for Vreverse rotation. Aftera curing period at maximum pressure, reversed to exert downward pressureupon piston 2b Yvia a tube 34"'and to drain the fluid from the mastercylinder 2a via tube 37 while bypassing a limited quantity of fluid fromthe pres-sure'valve 29 to Vthe reservoir through tubes 32 and 37. Thepressure in the valve thus drops, the diaphragm' 29a thereupon raisingthe plunger 29' to its original position to re-open the uidpath to thecylinders 14; this again tensions the cables 7 upon the descent bedplate 3 to lower the platens gradually and at different rates. As thebed plate 3 comes to rest in its bottom position, switch 26' and,therefore, solenoids i12. to normal, thus permitting the pawls 11 tore-engage the teeth of ratchets 24 as the bed plate 3 rises for anotherpress cycle.

Y In FIGS. 2 and 3 I illustrate another embodiment of theinvention'wherein the bed plate 3 is adapted to compress a plurality ofsheets 21 carried by the platens 4 against `a head plate as describedhereinabove. The platens are again supported from four step pulleys 5 bycables 6 secured to the platens 4 at bars 22. In the present embodiment,however, the tractive elements 7, adapted to drive the pulleys 5, passunder idler pulleys 38 not displaceablev in a vertical direction. Theelements 7 are ioined to a pair of `yokes 17 (one ofwhich is shown)extending at least partially beneath and transverse to the bed plate 3,these yokes being elevatable by a pairV of hydraulic cylinders 16b whosepistons 16a bear thereon from below. of master cylinders 2a. ment forthe present embodiment is further illustrated in FIG. 4.' Each platen 4and the'head plate 20 is provided witheone of a plurality ofseries-connected switches 41a to l41h which are closed by the engagementof their armatures with the next-lower platen 4 or with the bed plate 3.A second set of switches 37a to 37h, closable directly by platens 4 orbed plate 3 and connected in parallel, are on each platen 4 and the headplate 20.

A normally closed limit switch k45 is mounted on the base of the pressso as to be open-circuited upon the downstroke of yoke 17 by a stud43'carried thereon. The parallel combination of switches. 37a to 37h isconnected in series with the drive Aand with a source 43 of electriccurrent, while the series-connected switches 41a to 41h areconelectromagnetic holding relay 55 andthe battery 43. 'Ihe relaycontacts 55a, parallel-connected `solenoids 12, battery'43, while switch45 the holding circuit of relay 55. l Y Y v valve 33 maybe downwardmovement of the the reduced pressure in the valve29 restores Bed plate 3is also carried on pistons 27.1:V The electrical circuit arrange-j motor`44 of a hydraulic distribut? In operation, hydraulic uid from reservoir27 is forced by pump 28 through a transmission tube 50 to the mastercylinders 2a Ywhile l1617 via tube 52, Ythereby raising the yokes 17 andthe bed 3. It will be apparent that the owvof iluid may be so regulatedas to permit the yokes -to raise the bed plate 3 or to cause thesubstantially simultaneous elevation of both yokes and the bed plate.The press thus 'closes until one or more of the parallel switchesV 37ato 37hroperate.

Thereby an electrical circuit is closed to drive motor 44 which Yadjuststhe distributing flow of fluid to cylinders 16b while continuing theunder increased pressure to master cylinders 2q. YThe upward motion ofthe yokes 17 thus ceases whereas the bed plate 3 commences itscompression stroke, thereby slackening the cables 6 and.7 to disengagethe spacer apparatus. At the conclusion of the compression stage, i.e.when all the sheets have been compressed to their predeterminedthicknesses, the series-connected switchesl 41a to 41hrclose to completea circuit to the winding of relayV 55, thereby closing the contacts 55a,55b and op-V erating the solenoids 12 to withdraw the pawlskll from`engagement with their ratchet rings Yas described with f reference tothe preceding embodiment. After -a predetermined curing timehas elapsed,the motor 44 in its continuing operation blocks the fluid ow tocylinders' 2a vand opens a return path from the latter to the reservoiry27 via return tube 56. The bed plate thus commences to lower,entraining in the'latter part of its descent the yokes 17 to re-activatethe spacer mechanism. The distributing valve 40 may be designed tointroduce uid at this time to the tops of cylinders 1'6b and 2a viatubes 53 and 51, respectively, press opens. As the yokes 17 and the bedplate 3 attain the kfully opened position normally closedY switch 45 toYdeactivate the relay 55,

Y 4thereby releasing pawls 11 and restoring the spacer as- Abutments 57(only one shown) on the frame 1 of the Y Y press serve las safety stopsfor the yokesA 17 to insure a Y slackening of the cables even uponfailure of the switching Y circuit 37a tov 37h. IIn cases where majordifferences in sheet thickness and partialloading of the press are noproblem, such abutments (positioned, desired, atY a somewhat lowerlocation on the frame) may also be used in lieu. of such switchingcircuit as means for deactivating the spacing apparatus Iat apredetermined point in the 'ascent of the bed plate 3.V Under suchcircumsoY stances it would also be possible to dispense with `all butone of the switches 37a to 37h and to mount the remain- Y ing switch onthe frame 1 for actuation by Vone of 'the i' 'yokes 17 (FIG. 2) or bythe bed plate V3fV (FIG. l or 2) as the latter reaches the point atwhich slackening of the cables is to occur. These and other modications,which will beY readily apparent to persons skilled inthe art, areintended to be included within the spirt and scope Yof the` invention'except as further limited by the appended claims. Y

I claim: Y

1. A multi-platen press for the compaction of sheet materials,comprising ya frame; a pluralityof vertically spaced sheet-supportingplatens held on sa-id trame for vertical movement; a xed stop on saidame aboveV said platens; plunger means below said platensoperable to actupon the -lowermost platen in a manner pressing all of said platens andthe intervening sheets against oneV another and said stop;operating'means for raising said plunger means; transmission meanscoupled with said plunger means for raising said platens simultaneouslywithY said plunger means -at rates decreasing progressively from thelowermost to the uppermost platen whereby the separations between saidplatens concurrently decrease uponY the rise of said plunger means, saidtransmission means f comprising a stepped pulley, Va set of cablespassing a part of the fluid enters the cylinders Y valve 40 to shut oitheY iowY to increase the rate at which the Y of the press, plunger 43tripsthe Y around respective stops of said pulley and lanchored torespective platens, and coupling means including a further cablereleasably interconnecting said plunger means and said pulley forrotating the latter upon a rise of the former; tensioning means bearingupon said further cable in a rst direction tending to raise said platensthrough said transmission means for maintaining the connection betweensaid pulley and said plunger means during at least part of the rise ofsm'd plunger means; and automatic means coupled with said tensioningmeans and controlled by said operating means for temporarilyinactivating said coupling means at an intermediate point in the riseoi' said plunger means by slackening said further cable through adisplacement of said tensioning means in a second direction oppositesaid iirst direction.

2. A press according to claim l wherein said operating means comprises ahydraulic system.

3. A press according to claim 2 lwherein said automatic means isprovided with an Vactuating element responsive to a rise in thehydraulic pressure of said system due to beginning compaction of atleast one of said sheets.

4. A press according Ytoclam 1, further comprising switch meanscontrolled by at least one of said platens for operating said automaticmeans.

5. A press according to claim 1 wherein said tensioning means comprisesa deiiecting roller engaged by said further cable and said automatic-means includes hydraulically displaceable support means for saiddeecting roller.

6. A press according to claim 1 wherein said plunger means comprises abed plate, said tensioning means comprising a follower member upwardlydisplaceable by said operating means along with said bed plate during aportion of the ascent of the latter, said further cable being anchoredto said follower member.

7. A press according to claim 6 wherein said follower member comprises ayoke embracing said bed plate from below in a lower position of said bedplate, said automatic means land said operating means respectivelyincluding first and second hydraulic systems for respectively raisingsaid yoke and said bed plate, said tensioning means vfurther includingstop means for inactivating said first hydraulic system.

8. A press acccording to claim 1, further comprising check means forlocking said stepped pulley against reverse rotation and release meansfor de-activating said check means substantially upon attainment of itshighest point by said plunger means.

9. A press according to claim 8 wherein said check means comprises a setof ratchet teeth on said pulley and pawl means yengageable with saidratchet teeth, said release means including an electromagnetic devicefor retracting said pawl means from said ratchet teeth.

References Cited in the file of this patent UNITED STATES PATENTS2,941,249 Rogers June 2l, 1960

